Shotgun shell wad with powder pocket



Feb. 15, 1966 e. HERTER SHOTGUN SHELL WAD WITH POWDER POCKET Filed April 27. 1964 FIG 5 W i/m United States Patent 3 234,877 SHOTGUN SHELL WAD WITH POWDER POCKET George L. Herter, Waseca, Minn., assignor to Herters Ina, Waseca, Minm, a corporation of Minnesota Filed Apr. 27, 1964, Ser. No. 362,688 11 Claims. (Cl. 102-95) This invention relates to firearm cartridges and particularly to an improved shotgun shell wad capable of housing the explosive charge. An object of this invention is to provide an improved wad of the type described which is designed to reinforce the powder area and tends to eliminate the pressure on the sides of the cartridge casing proper.

Another object is to provide a wad of the type described which will increase the effective force of the explosive charge.

Still another object is to provide an improved wad of the type above described which not only reinforces the powder area and increases the effective force of the powder charge, but also provides a gas seal with the gun bar= rel, cushions the initial explosive impact or shock, minimizes engagement of the shot with the barrel, improves the symmetry of the shot patterns, and assures a true line of travel of the wad through the barrel by preventing cocking of the wad as it travels therethrough.

Still another object is to provide a wad having a powder enclosing pocket which significantly reinforces the powder area so as to simplify the construction of the outer casing or shell of said cartridge.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawing wherein like reference characters refer to the same or similar parts throughout the several views and in which:

I FIG. 1 is a longitudinal diametrical sectional view of a shotgun cartridge incorporating one preferred embodiment of the wad of this invention;

FIG. 2 is a cross-sectional view of the wad of FIG. 1 taken on the line 2-2 of FIG. 3;

' FIG. 3 is a perspective view of the upper part of the wad of FIG. 1;

FIG. 4 is a perspective view of the lower part of the wad of FIG. 1; and

FIG. 5 is a partial longitudinal sectional view of the cartridge of FIG. 1 immediately after firing and illustrating the cushioning action of the wad.

Referring to the drawing for a more detailed description of this invention, a complete shotgun cartridge is illustrated in FIG. 1. Said cartridge includes an outer casing or shell C of integral formation and preferably of plastic material such as polyethylene, said casing including a generally cylindrical tubular side wall 10 and a base 11 having a conventional primar cap 12 concentrically mounted therein. However, it will be understood that any suitable casing can be used with the wad of this invention.

The wad of this invention which is shown in the accompanying drawing is of molded construction and formed of compressible, resilient plastic material such as polyethylene. The illustrated wad consists of an upper part A and a lower part B which are de-tachably joined in a manner hereinafter described. The upper part A consists of an upper shot cup and a lower gas sealing cup, the upper shot cup and lower sealing cup being interconnected by an axially extending shank or rod 13 extending therebetween, said rod having a flange or collar 14 formed thereon and extending radially therefrom, said collar being disposed approximately midway between and in spaced relationship from both the upper and lower cups. The upper shot cup is open at its upper end and includes a generally cylindrical tubular side wall 15 having a pair of diametrically opposed longitudinally oriented slots 16 formed therein and a base or end wall 17.

It is important to note that the slots extend substantially the full length of the side wall 15 but terminate just short of the outer end thereof so that they are not in communication with the marginal edge of the side wall and are completely enclosed thereby. Thus, the outer end of the shot cup is of continuous integral annular formation and therefore will not tend to materially distort or flare out. This is particularly important in guns having choke mechanisms with an open space between the end of the barrel and the start of the choke tube. If these slots extended all the way to the outer edge of the upper cup, this outer end would distort and lodge or mushroom around the choke tube. However, because the openings 16 are completely enclosed, this cannot occur. The wall 15 and base 17 define a recess or chamber 18 for receiving, housing and enclosing the shot pellets 19, which pellets may rest directly on the base 17, without using any of the conventional filler or separator wads between the base 17 and the pellets although such separator wads can be used if desired.

The slots 16 are provided to permit any air or lubricant present in chamber 18 at the time of firing to escape or be expelled from said chamber. Although the openings in the shot cup Wall are preferably slotted as shown, it will be understood that openings having geometrical configurations, shapes, direction or number other than illustrated can be successfully utilized within the scope of this invention. Thus, the slots could be spirally arranged, or a plurality of small perforations could be vertically or spirally arranged to replace slots 16.

The gas sealing cup comprises a cup within a cup or a pair of downwardly facing concentric cups having a common base 20. The outer or larger cup has a depending generally cylindrical downwardly tapered skirt, wall or flange 21 which is laterally spaced from the generally cylindrical wall 22 of the inner cup so as to form an annular groove therebetween. Since the wad is formed of somewhat flexible plastic material, the wall 21 of the outer cup expands upon the initial explosion of the charge and moves into tight sealing engagement with the barrel of the gun. The inner cup serves as a dome to accornmodate the powder and its wall 22 also serves to reinforce the base 29 so that it will not rupture or break upon the initial explosion of the powder. The walls 21-22 also function as the female portion of a snap joint for detachably fastening the two parts A and B of the wad together in a manner described in more detail hereinafter.

The lower part or section B of the wad forms a powder cup and has a generally cylindrical side wall 23 and a base or end wall 24, the juncture between the side wall and base being rounded as shown for strength of construction and for complementary engagement with the internally rounded corner of the casing C. The base 24 of the powder cup has an opening 25 concentrically formed therein for receiving and fitting over the primer cap 12 preferably in close fitting relationship therewith. In the V illustrated embodiment, the wad sections A and B are detachably fastened together by snap joint means. However, other fastening means may be utilized within the scope of this invention. These fastening means are such that the upper and lower parts A and B can be readily fastened together once the charge of powder 26 has been placed therein. However, the fastening means are strong enough to withstand separation or disengagement of the upper and lower parts A and B upon the explosion of the powder and will not disengage even upon the outward movement of the wall 21 into sealing engagement 3 with the barrel so that the entire wad illustrated including the upper and lower parts A and B thereof will move together through and out of the gun barrel as a unit.

The connection between the upper and lower parts A and B is such that there is virtually no escape of gas through the side walls of the powder cup.

The illustrated snap joint for fastening parts A and B together consists of a female part formed by the aforementioned concentric walls 2122. The side wall 23 has a reduced upwardly tapered upper end portion 23a of substantially the same cross-sectional size and shape as the annular groove between the walls 21-22, the reduced portion 23:: serving as the male part of the snap joint. An annular groove 21a is formed on the inner face of the Wall 21, and an annular rib 23b is formed on the outer face of the reduced wall portion 23a for seating in the groove 21a to complete the snap joint construction. Since the walls 2122 are resilient, they will move apart a sufiicient distance to enable the male part 23:: to be inserted therebetween and rib 23b to be snapped into locking relationship with the groove 21a. The walls 15 and 23 and the collar 14 are preferably of the same outside diameter, and are in close fitting sliding relationship with the side wall of the casing C. The connecting rod 13, the powder cup, pellet cup and collar 14 are in axial alignment and concentrically arranged with respect to each other.

Since the only place that the gas can escape from the powder pocket is through the opening 25 in the base 24 thereof, and since this opening is of restricted size, part B has a contracted vent and serves or functions as a jet nozzle whereby the restricted opening 25 and the gas escaping therethrough serves to substantially increase the effective forward thrust of the ignited powder on the wad and on the pellets carried thereby so as to increase the efficiency of the explosive charge and the velocity of the pellets.

The pellets 19 are housed within the upper shot pocket and are confined therewithin by a sealing wad 27, which sealing wad is held in place by the inturned outer end 10a of the cartridge casing 10.

It will be appreciated that the side wall structure defining the powder pocket reinforces the powder area and reduces the pressure on the side wall 10 of the shot shell casing.

The base 17 of the shot cup is sufiiciently resilient so that when axial pressure is applied thereto by the interconnecting rod 13 that it will tend to bow inwardly so as to absorb the force applied thereto by the rod. The material from which the wad is made is preferably sufiiciently compressible so that the rod 13 will be longitudinally compressed somewhat by the force applied thereto by the ignited powder.

When the powder is ignited, the explosion gases bear against the resilient walls 10 and 22 and push them radially outwardly. This pressure causes the wall 21 (which is not directly contacted by the gases) to be pushed outwardly into gas sealing engagement with the gun barrel. The pressure on the wall 22, in addition to contributing to the sealing movement of wall 21, also serves to maintain locking pressure on the male part 23a of the snap joint so as to prevent disengagement of parts A and B at the time of firing.

Thus, the design of the upper part A and the interconnection of the shot cup and sealing cup by the narrow connecting rod 13 provides a resilient compressible design which provides for relative axial movement between the shot cup and the sealing cup (and the part B attached thereto) so as to cushion or absorb the initial explosive impact at the moment of discharge of the powder. Part of the explosive impact is absorbed by the yielding of the base of the shot cup and the remainder of the impact is absorbed by the rod itself which actually is longitudinally compressed and slightly flattened out at the moment the powder is exploded. The bowing in of the shot cup base and the compression of the rod at the time of firing are clearly illustrated in FIG. 5.

The intermediate collar 14 is provided to prevent or minimize the cocking of the wad as it travels through the barrel. This provides for true travel of the wad through the barrel in a straight line to minimize the drag and to produce maximum efficiency.

The entire ilustrated wad (both parts A and B) accompanies the pellets as they travel through the gun barrel, the pellets not becoming completely disengaged from the shot pocket until both the wads and pellets have been discharged from the gun barrel. Because of this accompanying of the pellets by the wad, the wad serves as a protective lining between the pellets and the gun barrel so as to minimize or completely eliminate contact of the pellets with the gun barrel. Because of this, there is no deformation of the shot and therefore a truer and more symmetrical shot pattern is produced. Upon release from the gun barrel, the air resistance strips the wad from the pellets.

Thus, in use, the lower sealing cup of part A- in combination with part B form a powder pocket which cornpletely encloses the powder charge so as to reinforce and protect the cartridge casing and at the same time serve as a jet nozzle for the gas which escapes through the small restricted primer enclosing opening 25 to maximize and increase the effective propellant force of the powder. The problem of gas leakage is virtually eliminated. The shot cup protects the pellets from engagement with the gun barrel so as to prevent shot deformation and improve the shot pattern. The intermediate collar prevents cocking of the wad, and the cushion design enables the initial shock or impact of the explosive charge to be absorbed so as to prevent destructive rupturing or tearing of the wad itself at the moment of explosion. The wads of this invention are of such durable construction that they can be reused where desired and can be readily eliminated from all gun barrels including those having choke mechanisms thereon.

It will also be understood that although the preferred embodiment of this invention includes the shot pocket and the anti-cocking and shock absorbing structure previously disclosed and illustrated in the drawing, it is to be clearly understood that the invention is not necessarily limited to this precise construction. The scope of the invention is basically directed to an overpowder wad which has a powder enclosing pocket with a restricted gas escape opening in the base thereof, and any wad incorporating this basic construction is intended to come within the scope of this invention. Also, it is to be understood that the invention is not limited to a powder pocket formed in two parts as illustrated. As previously mentioned, the two part construction is preferred to facilitate the loading of the charge. However, an integral one piece powder cup is intended to come within the scope of this invention.

As previously mentioned, means other than the particular snap joint illustrated and described herein can be used to fasten the powder pocket or part B to the upper part A. Thus, for example, screw thread means, other types of snap-joint means or tight fitting wedge means may be used to fasten part B to part A.

Although the wad of this invention is preferably so designed that the powder pocket B remains attached to part A after the ignition of the powder and travels out of the gun attached to part A, improved beneficial results are also achieved if the powder pocket B does not leave the gun with part A, provided that parts A and B are: attached to each other when the powder is ignited and do not become detached until after said ignition. Even if parts A and B become detached after ignition of the powder, the powder cup 13 still initially seals the powder gases and takes the pressure off the shell case. to prevent damage thereto.

The intended and desired improved beneficial results will not be attained if powder pocket B is not attached to part A at the time the powder is ignited. If parts A and B are not attached, the powder gases simply go around and past the powder pocket and damage the cartridge case. Thus, the parts A and B must remain attached at least long enough to protect the casing from the initial impact of the explosion gases.-

The powder pocket B can be anchored only to part A, or it may be anchored to both part A and the base of the cartridge, as by snapping part B onto a protrusion of the primer cup jacket or onto a grooved primer, or by just pressure fitting the part B onto a primer pocket extrusion or the primer itself. However, if the part B is designed to remain anchored to the base after the powder is ignited, then the attachment means between parts A and B must be such as to permit part A to detach itself from part B after ignition of the powder.

Also, the primer 12 does not necessarily have to actually be inserted in the opening 25 of the powder pocket B as illustrated. The intended advantages will also be realized if part B simply overlies the primer with the powder in contact with said primer.

Although the wad of this invention is particularly applicable to shot gun cartridges, it can also be used in other types of cartridges for both small and large guns, including small arms ammunition and heavy-duty field type shells.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various par-ts without departing from the scope of my invention.

What I claim is:

1. A wad for a firearm cartridge having a propellant charge and a primer cap in the base thereof, said wad comprising an upper obturating portion adapted to overlie the propellant charge of the cartridge and a lower portion, said portions defining a chamber for receiving and substantially completely enclosing said charge, means for detachably fastening said portions together whereby said portions will remain fastened together when said charge is ignited, said lower portion having an opening therein adapted for substantial alignment with the primer cap of the cartridge and of a cross sectional area not substantially larger than that of said primer.

2. A wad for a firearm cartridge having a propellant charge and a primer cap in the base thereof, said wad comprising two sections, said sections defining a chamber for receiving and substantially completely enclosing said charge, means for detachably fastening said sections together whereby they remain fastened together when the charge is ignited, and an opening in said sections for enabling said charge to make contact with said primer.

3. A wad for a firearm cartridge having a propellant charge and primer cap in the base thereof, said wad comprising an upper and a lower section adapted to house and enclose said charge therewithin, said upper section being adapted to overlie said charge and including a pair of concentric downwardly directed laterally spaced apart annular generally cylindrical walls, an annular groove formed on the inside it the outer of said walls, said lower section including a generally cylindrical side wall, the upper end portion of said side wall being adapted for insertion into the space between said depending concentric walls of said top section, said upper end portion of said side wall having an annular rib formed on the outer periphery thereof and adapted to seat in, said annular groove, said upper end portion and depending pair of walls forming a snap joint therebetween, said lower section also having an opening formed therein concentric with its side wall, said opening being of substantially the same size as the primer cap and adapted to receive same.

4. The wad of claim 3, wherein the concentric walls of the upper section and the side wall of the lower section 6 are resilient and capable of expanding under the influence of the ignited charge and moving the outer of said concentric walls into sealing engagement with the gun barrel.

5. A wad for a firearm cartridge having a propellant charge and a primer cap in the base thereof, said wad comprising two sections, said sections defining a chamber for receiving and substantially completely enclosing said charge, snap fastening means for detachably fastening said sections together whereby they remain fastened together when the charge is ignited, and an opening in said sections for enabling said charge to make contact with said primer.

6. A firearm cartridge wad comprising a first generally cylindrical tubular body defining a chamber for receiving the propellant charge of said cartridge, a first end wall enclosing one end of said chamber and adapted to overlie said charge, and a second end wall enclosing the other end of said chamber and adapted to underlie said charge, said second wall having an opening therein substantially concentrically disposed with respect to said body, and a second generally cylindrical tubular body disposed above, connected to, and concentric with said first body, said second body having an open upper end and adapted to house the projectile means of said cartridge, said first body being axially movable towards said second body under the influence of the ignited charge, said first and second bodies are interconnected by a rod disposed concentrically thereof, said rod being longitudinally compressible and the portion of said second body immediately adjacent said rod being yieldable under the influence of the ignited charge.

7. The Wad of claim 6, including a circular disk mounted on said rod and concentric therewith and spaced from both of said bodies.

8. A firearms cartridge wad comprising an upper and a lower section adapted to house and enclose the propellant charge of the cartridge therewithin, said upper section being adapted to overlie said charge and including a pair of concentric downwardly directed laterally spaced apart annular generally cylindrical walls, said lower section incuding a generally cylindrical side wall, the upper end portion of said side wall being adapted for insertion into the space between said depending concentric walls of said top section, said walls being provided with cooperating fastening means for detachably fastening the upper and lower sections together, said lower section also having an opening formed therein concentric with its side wall and of smaller area than the cross-sectional area of said cylindrical side wall.

9. A firearm cartridge wad comprising wall structure defining an upper generally cylindrical tubular body having an open upper end and a lower end wall defining a housing adapted to house the projectile means of said cartridge, a second generally cylindrical tubular body having an upper end wall in common with the lower end wall of said first tubular body interconnecting said first tubular body and said second tubular body, said second tubular body defining a chamber for receiving the propellant charge of said cartridge and having a lower end wall including a restrictive opening in the bottom thereof for the escape of gases resulting from the ignition of said charge, said structure functioning as a jet nozzle so that the escape of gases through said opening increases the forward thrust of said wad.

10. The wad of claim 9, wherein the common end wall of said interconnected propellant chamber and projectile housing is movable towards said housing under the influence of the ignited charge.

11. The wad of claim 9, wherein said wall structure inincludes a generally cylindrical tubular wall portion adapted to be moved outwardly into sealing engagement with gun barrel by the ignited charge.

(References on following page) 7/1954 France. 2/1961 France.

BENJAMIN A. BORCHELT, Primary Examiner.

France. France. Germany. Great Britain.

R. F. STAHL, Assistant Examiner. 

1. A WAD FOR A FIREARM CARTRIDGE HAVING A PROPELLANT CHARGE AND A PRIMER CAP IN THE BASE THEREOF, SAID WAD COMPRISING AN UPPER OBTURATING PORTION ADAPTED TO OVERLIE THE PROPELLANT CHARGE OF THE CARTIRIDGE AND A LOWER PORTION, SAID PORTIONS DEFINING A CHAMBER FOR RECEIVING AND SUBSTANTIALLY COMPLETELY ENCLOSING SAID CHARGE, MEANS FOR DETECHABLY FASTENING SAID PORTIONS TOGETHER WHEREBY SAID PORTIONS WILL REMAIN FASTENED TOGETHER WHEN SAID CHARGE IN IGNITED, SAID LOWER PORTION HAVING AN OPENING THEREIN ADAPTED FOR SUBSTANTIAL ALIGNMENT WITH THE PRIMER CAP OF THE CARTRIDGE AND OF A CROSS SECTIONAL AREA NOT SUBSTANTIALLY LARGER THAN THAT OF SAID PRIMER. 